Silvia Ramos is an MD PhD with a diverse portfolio including a strong clinical formation in internal medicine, autoimmune disease as well as a solid training in basic science of reproductive biology and clinical embryology. She is committed to devoting herself to the study of infertility of unexplained basis. Silvia's long-term-career goal i to be an independent funded scientist, doing basic research on reproductive biology and RNA metabolism with a meaningful goal to translate into providing explanations of human infertility of unexplained basis. Silvia's short-term career goals are to 1) gain a more specific and in depth knowledge on RNA metabolism; 2) master the techniques of knocking down specific proteins either using siRNA or shRNA; 3) generate a genetic engineered mouse to test the model in vivo; 4) obtain additional training in responsible conduct of research; and 5) develop writing skills, grantsmanship, preliminary data and publications to be credible as the PI of an R01 and establish herself as a national leader in the reproductive and RNA field. The proposed research plan, career development activities, mentorship team, and institutional environment are all uniquely suited to assist the applicant in achieving these goals. The goal of this project is to investigate the regulation of a specific implantation factor, Leukemia Inhibitory Factor (LIF). LIF is required for successful embryonic implantation to the uterus in mice. Our hypothesis is that Leukemia Inhibitory Factor (LIF) is regulated at the post-transcriptional level. In aim 1, the PI wll selectively overexpress and down-regulate each of the ZFP36 proteins (TTP, ZFP36L1 and ZFP36L2) in human cell lines to determine whether LIF mRNA can be destabilized by these proteins. In Aim 2, the PI will identify and characterize which sequences of LIF mRNA are involved in binding to ZFP36 proteins. In Aim 3, the PI will test the biological relevance of LIF mRNA destabilization by ZFP36 proteins during the implantation by creating a mouse model expressing higher than normal levels of one ZFP36 protein in uterine epithelial cells. The expected outcome of this proposal is an improved knowledge of the mechanisms by which a specific implantation factor, LIF, is regulated; and how this regulation influences the process of early embryo implantation. To support Dr. Ramos's career development, she will pursue coursework in basic advanced molecular biology, modeling human disease in mice, and research ethics. The mentorship team, which includes internationally-recognized, independently-funded investigators with expertise in gene regulation and RNA metabolism (Marzluff); and generation of genetically engineered mice of human disease and biology of implantation (Caron), will guide Dr. Ramos's research and career development. The research environment will provide a productive, collegial, and collaborative atmosphere ideal for pursuing the above research and training goals.